A traditional system for irrigating a large agricultural area comprises a series of sprinkler pipes with sprinkler heads at appropriate intervals along the pipe. Covering the entire area requires manually disconnecting each length of pipe, moving each length to a new location, and then reconnecting the pipes at the new location. Such a system is typically moved at regular intervals to cover the entire irrigated area during a fixed period.
More automated irrigation systems are now common. In an automatic system, lengths of irrigation pipe are supported above the ground by driven wheel or carriage assemblies. The supported lengths are connected in a line to move across an irrigated area. Motors and controls are provided to move the irrigation line, either automatically or at an operator's direction. Typical mobile irrigation systems are configured to move laterally or to move about a fixed pivot to cover a large irrigated area.
The coverage of a common mobile irrigation system as described above is often limited by obstacles that block the movement of the irrigation line. Utility poles are the most common type of obstacle. "Utility poles" for high-voltage transmission lines are often more than just a single pole. Instead, they may have four legs and span a large area. For example, the diagonal measurement of some four-leg utility poles is nearly 30 feet.
The existence of such an obstacle on a given parcel of land creates a serious inconvenience and expense. It either limits the useful irrigated area of the land or requires the added expense of manual irrigation. The significance of these limitations is often so great as to decrease the actual value of the land.
The invention described below allows reclamation and irrigation of farm land that had previously been blocked by utility poles or other obstacles. The invention is compatible with existing rotating and lateral move mobile irrigation systems and may be designed to function automatically without operator intervention. Furthermore, the invention is simple and efficient, adding negligibly to the overall cost of a modern irrigation system.